Add File-Overview comments, move out of place comments

Server/Entities/Character.cs

@@ -1,16 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.ComponentModel.DataAnnotations;
-using System.Text;
-
-namespace reallife_gamemode.Server.Entities
-{
-    public class Character
-    {
-        [Key]
-        public int Id { get; set; }
-        public int UserId { get; set; }
-        public string Name { get; set; }
-        public byte Gender { get; set; }
-    }
-}